Lexical priming in picture naming of young children who do and do not stutter

Exploring the Activation of Target Words in Picture Naming in Children Who Stutter: Evidence From Event-Related Potentials

PURPOSE

Target word activation in picture naming was explored in children who stutter (CWS) and typically fluent children (TFC) using event-related potentials (ERPs).

METHOD

A total of 18 CWS and 16 TFC completed a task combining picture naming and probe word identification. On each trial, a picture-to-be-named was followed by an auditory probe word-to-be-identified; the probe was identical (Identity condition) or Unrelated to the picture name. ERPs were recorded from probe onset. Attenuation of the N400 ERP component was predicted to Identity versus Unrelated trials (N400 priming). Between-groups differences in amplitude, timing, and topography of N400 priming were explored.

RESULTS

Naming was more accurate on Identity versus Unrelated trials. Probe word identification accuracy was not affected by Condition. N400 priming was detected, indicating that self-generated picture names facilitated semantic processing of identical probes. This effect was larger in amplitude in CWS versus TFC. Unexpectedly, an N400-preceding, frontally maximal, positive-going ERP component-associated with expectancy processing-was larger in amplitude to Unrelated versus Identity trials. This effect was smaller in CWS versus TFC.

CONCLUSIONS

A larger N400 priming effect in CWS versus TFC reflects a tendency toward more extensive semantic processing in picture naming in CWS. A smaller Condition effect on frontally maximal, positive-going, N400-preceding ERP activity in CWS versus TFC indicates a reduced ability to form expectancies about the lexical and/or phonological identity of probe words in CWS. Both effects may point to inefficient activation of target words in picture naming in CWS.

Picture naming test through the prism of cognitive neuroscience and linguistics: adapting the test for cerebellar tumor survivors-or pouring new wine in old sacks?

A picture naming test (PNT) has long been regarded as an integral part of neuropsychological assessment. In current research and clinical practice, it serves a variety of purposes. PNTs are used to assess the severity of speech impairment in aphasia, monitor possible cognitive decline in aging patients with or without age-related neurodegenerative disorders, track language development in children and map eloquent brain areas to be spared during surgery. In research settings, picture naming tests provide an insight into the process of lexical retrieval in monolingual and bilingual speakers. However, while numerous advances have occurred in linguistics and neuroscience since the classic, most widespread PNTs were developed, few of them have found their way into test design. Consequently, despite the popularity of PNTs in clinical and research practice, their relevance and objectivity remain questionable. The present study provides an overview of literature where relevant criticisms and concerns have been expressed over the recent decades. It aims to determine whether there is a significant gap between conventional test design and the current understanding of the mechanisms underlying lexical retrieval by focusing on the parameters that have been experimentally proven to influence picture naming. We discuss here the implications of these findings for improving and facilitating test design within the picture naming paradigm. Subsequently, we highlight the importance of designing specialized tests with a particular target group in mind, so that test variables could be selected for cerebellar tumor survivors.

How to cut the pie is no piece of cake: Toward a process-oriented approach to assessment and diagnosis of speech sound disorders

BACKGROUND

'Speech sound disorder' is an umbrella term that encompasses dysarthria, articulation disorders, childhood apraxia of speech and phonological disorders. However, differential diagnosis between these disorders is a persistent challenge in speech pathology, as many diagnostic procedures use symptom clusters instead of identifying an origin of breakdown in the speech and language system.

AIMS

This article reviews typical and disordered speech through the lens of two well-developed models of production-one focused on phonological encoding and one focused on speech motor planning. We illustrate potential breakdown locations within these models that may relate to childhood apraxia of speech and phonological disorders.

MAIN CONTRIBUTION

This paper presents an overview of an approach to conceptualisation of speech sound disorders that is grounded in current models of speech production and emphasises consideration of underlying processes. The paper also sketches a research agenda for the development of valid, reliable and clinically feasible assessment protocols for children with speech sound disorders.

CONCLUSION

The process-oriented approach outlined here is in the early stages of development but holds promise for developing a more detailed and comprehensive understanding of, and assessment protocols for speech sound disorders that go beyond broad diagnostic labels based on error analysis. Directions for future research are discussed.

WHAT THIS PAPER ADDS

What is already known on the subject Speech sound disorders (SSD) are heterogeneous, and there is agreement that some children have a phonological impairment (phonological disorders, PD) whereas others have an impairment of speech motor planning (childhood apraxia of speech, CAS). There is also recognition that speech production involves multiple processes, and several approaches to the assessment and diagnosis of SSD have been proposed. What this paper adds to existing knowledge This paper provides a more detailed conceptualisation of potential impairments in children with SSD that is grounded in current models of speech production and encourages greater consideration of underlying processes. The paper illustrates this approach and provides guidance for further development. One consequence of this perspective is the notion that broad diagnostic category labels (PD, CAS) may each comprise different subtypes or profiles depending on the processes that are affected. What are the potential or actual clinical implications of this work? Although the approach is in the early stages of development and no comprehensive validated set of tasks and measures is available to assess all processes, clinicians may find the conceptualisation of different underlying processes and the notion of potential subtypes within PD and CAS informative when evaluating SSD. In addition, this perspective discourages either/or thinking (PD or CAS) and instead encourages consideration of the possibility that children may have different combinations of impairments at different processing stages.

The Pausing Strategies in Chinese Preschool Children's Narratives

PURPOSE

Language production, a dynamic process involving real-time language processing, is crucial for children's language and communication development. To explore the early development of children's real-time language production, this study investigated Chinese preschool children's pausing strategies in narratives and their associations with verbal working memory and vocabulary abilities.

METHOD

A picture-elicited narrative task was employed. Sixty Mandarin-speaking children aged 4-5 years were asked to tell a story according to the book Frog, Where Are You? The pausing types and positions in narratives were coded and analyzed. Additionally, children's verbal working memory and vocabulary were measured.

RESULTS

The results showed that 4- to 5-year-old children prefer to use silent pauses and tend to produce pauses within clauses. The total frequency of pausing decreases with age and shows a significant gender difference. Girls prefer to use within-clause pauses, whereas boys prefer to use between-clause pauses. More importantly, children's pausing frequency is closely associated with their verbal working memory and vocabulary, in which working memory plays a more important role.

CONCLUSIONS

This study is a first-step exploration of pausing strategies in 4- to 5-year-old Chinese children's narratives. The developmental characteristics of pausing strategies shown in typically developing children serve as a crucial reference for interventions for children with language deficits.

Rate of Stuttering and Factors Associated With Speech Fluency Characteristics in Adult Struggling Readers

Stuttering is a disorder that affects about 1% of the population and manifests as speech disfluencies. Reading difficulties and disabilities are commonly found in this population. Nonetheless, speech disfluencies have not been explored in adult struggling readers (ASRs). In the current study, we examined the rate of stuttering in ASRs as well as the relationships between their speech fluency and reading skills. A total of 120 participants were interviewed about their experiences with reading and administered standardized reading and reading-related assessments. Speech fluency and the criterion for stuttering were based on the interview. About 18.3% of the sample met the criterion for stuttering. ASRs who stutter (ASRs-S) and ASRs who do not stutter (ASRs-NS) did not differ in their reading and reading-related skills. ASRs-S had higher rates of negative correlations between reading and reading-related skills compared with ASRs-NS. Correlation patterns between performance on standardized assessments point to higher rates of uneven skills or dissociations in ASRs-S. These findings may have implications for the assessment and instruction for ASRs.

Adults Who Stutter Show Diminished Word Fluency, Regardless of Mode

PURPOSE

Language abilities have long been thought to be weaker in adults who stutter (AWS) compared to adults who do not stutter (AWNS). However, it is unknown whether modality affects language performance by AWS in time pressure situations. This study aimed to examine lexical access and retrieval abilities of AWS in oral and typed modes.

METHOD

Fifteen AWS and 15 well-matched AWNS completed computer-administered letter fluency tasks. Adults were asked to orally produce words that began with one of two letter targets and type words that began with one of two alternate letters. Conditions were counterbalanced across participants.

RESULTS

Generalized linear mixed-effects models were evaluated to determine the effects of group (AWS/AWNS), mode (oral/typed), and expressive vocabulary on letter fluency performance. Group predicted letter fluency such that AWS generated fewer items on both the oral and typed letter fluency tasks. Mode did not impact letter fluency results. Expressive Vocabulary Test scores predicted letter fluency similarly in both AWS and AWNS.

CONCLUSIONS

AWS were not penalized by oral task demands. AWS generated fewer items on the letter fluency tasks regardless of response mode, suggesting that they have weaker lexical access abilities. Furthermore, better expressive vocabulary skills were associated with better letter fluency performance in both groups.

Lexical Planning in People Who Stutter: A Defect in Lexical Encoding or the Planning Scope?

Developmental stuttering is a widely discussed speech fluency disorder. Research on its mechanism has focused on an atypical interface between the planning (PLAN) and execution (EX) processes, known collectively as the EXPLAN model. However, it remains unclear how this atypical interface influences people who stutter. A straightforward assumption is that stuttering speakers adopt a smaller scope of speech planning, whereas a defect in word retrieval can be confounding. To shed light on this issue, we took the semantic blocking effect as an index to examine lexical planning in word and phrase production. In Experiment 1, for word production, pictures from the same semantic category were combined to form homogeneous blocks, and pictures from different categories were combined to form heterogeneous blocks. A typical effect of semantic blocking showing longer naming latencies for homogeneous blocks than heterogeneous ones was observed for both stuttering and fluent speakers. However, this effect was smaller for stuttering speakers, when it was subject to lexical defects in stuttering. In Experiment 2, for a conjoined noun phrase production task, the pictures referring to the first noun were manipulated into homogeneous and heterogeneous conditions. The semantic blocking effect was also much smaller for stuttering speakers, indicating a smaller scope of lexical planning. Therefore, the results provided more evidence in support of the EXPLAN model and indicated that a smaller scope of lexical planning rather than lexical defects causes the atypical interface for stuttering. Moreover, a comparison between these two tasks showed that the study findings have implications for syntactic defects in stuttering.

Neural Processes Underlying Nonword Rhyme Differentiate Eventual Stuttering Persistence and Recovery

Purpose Phonological skills have been associated with developmental stuttering. The current study aimed to determine whether the neural processes underlying phonology, specifically for nonword rhyming, differentiated stuttering persistence and recovery. Method Twenty-six children who stutter (CWS) and 18 children who do not stutter, aged 5 years, completed an auditory nonword rhyming task. Event-related brain potentials were elicited by prime, rhyming, and nonrhyming targets. CWS were followed longitudinally to determine eventual persistence (n = 14) or recovery (n = 12). This is a retrospective analysis of data acquired when all CWS presented as stuttering. Results CWS who eventually recovered and children who do not stutter exhibited the expected rhyme effect, with larger event-related brain potential amplitudes elicited by nonrhyme targets compared to rhyme targets. In contrast, CWS who eventually persisted exhibited a reverse rhyme effect, with larger responses to rhyme than nonrhyme targets. Conclusions These findings suggest that CWS who eventually persisted are not receiving the same benefit of phonological priming as CWS who eventually recovered for complex nonword rhyming tasks. These results indicate divergent patterns of phonological processing in young CWS who eventually persisted, especially for difficult tasks with limited semantic context, and suggest that the age of 5 years may be an important developmental period for phonology in CWS. Supplemental Material https://doi.org/10.23641/asha.12682874.

Lexical diversity and lexical skills in children who stutter

PURPOSE

Numerous "small N" studies of language ability in children who stutter have produced differing conclusions. We combined test and spontaneous language data from a large cohort of children who stutter (CWS) and typically fluent peers, gathered from independent laboratories across the US, to appraise a variety of lexical measures.

METHOD

Standardized receptive and expressive vocabulary test data and spontaneous language samples from 99 pairs of CWS (ages 25-100 months), and age-, gender-, and SES-matched children who do not stutter (CWNS) were compared. Language sample transcripts were analyzed with four measures of lexical diversity. Correlations between lexical diversity measures and expressive vocabulary scores were also calculated.

RESULTS

On standardized tests of both receptive and expressive vocabulary, there were significant differences between CWS and CWNS. In contrast, on spontaneous language measures of lexical diversity, CWS did not differ in their lexical diversity, across analyses, compared to CWNS. Three of the four lexical diversity analyses, MATTR, VocD, and NDW, were significantly correlated with each other.

CONCLUSIONS

We were able to confirm prior findings of relative disadvantage on standardized vocabulary tests for a very large sample of well-matched CWS. However, spontaneous language measures of lexical diversity did not distinguish the groups. This relative weakness in CWS may emerge from task differences: CWS are free to encode their own spontaneous utterances but must comply with explicit lexical prompts in standardized testing situations.

A View of the Lexical-Grammatical Link in Young Latinos With Specific Language Impairment Using Language-Specific and Conceptual Measures

Purpose This study investigated the nature of the association of lexical-grammatical abilities within and across languages in Latino dual language learners (DLLs) with specific language impairment (SLI) using language-specific and bilingual measures. Method Seventy-four Spanish/English-speaking preschoolers with SLI from preschools serving low-income households participated in the study. Participants had stronger skills in Spanish (first language [L1]) and were in the initial stages of learning English (second language [L2]). The children's lexical, semantic, and grammar abilities were assessed using normative and researcher-developed tools in English and Spanish. Hierarchical linear regressions of cross-sectional data were conducted using measures of sentence repetition tasks, language-specific vocabulary, and conceptual bilingual lexical and semantic abilities in Spanish and English. Results Results indicate that language-specific vocabulary abilities support the development of grammar in L1 and L2 in this population. L1 vocabulary also contributes to L2 grammar above and beyond the contribution of L2 vocabulary skills. However, the cross-linguistic association between vocabulary in L2 and grammar skills in the stronger or more proficient language (L1) is not observed. In addition, conceptual vocabulary significantly supported grammar in L2, whereas bilingual semantic skills supported L1 grammar. Conclusions Our findings reveal that the same language-specific vocabulary abilities drive grammar development in L1 and L2 in DLLs with SLI. In the early stages of L2 acquisition, vocabulary skills in L1 also seem to contribute to grammar skills in L2 in this population. Thus, it is critical to support vocabulary development in both L1 and L2 in DLLs with SLI, particularly in the beginning stages of L2 acquisition. Clinical and educational implications are discussed.

Phonological and Semantic Contributions to Verbal Short-Term Memory in Young Children With Developmental Stuttering

Purpose The purpose of this study was to examine the verbal short-term memory skills of children who stutter (CWS) and children who do not stutter (CWNS) in 2 experiments, focusing on the influence of phonological and semantic similarity. Method Participants were 42 CWS and 42 CWNS between the ages of 3;0 and 5;11 (years;months). In Experiment 1, children completed the phonological similarity task, in which they listened to lists of phonologically similar and dissimilar words and then repeated them when signaled to do so. In Experiment 2, children completed another forward span task, the semantic category task, which is similar to the phonological similarity task, except that it consisted of lists of semantically homogeneous and heterogeneous words. Main dependent variables were cumulative memory span, proportion of errors by type, and speech reaction time (SRT) for correct responses. Results The CWS exhibited significantly shorter memory spans for phonologically dissimilar words and were less affected by the phonological qualities of the words than the CWNS in Experiment 1, based on the findings of both between-groups and within-group analyses. In Experiment 2, although the groups did not differ in their performance in either condition, within-group analyses revealed that the CWNS benefitted from semantic similarity, whereas the CWS did not. The between-groups difference in absolute difference scores, however, did not reach significance. The CWS produced more omissions and false alarms than the CWNS in both experiments, but the 2 groups of children were otherwise comparable in SRT, although the CWS exhibited overall faster SRT than the CWNS in Experiment 2. Conclusions Verbal short-term memory is one domain-general cognitive process in which CWS display weakness relative to typically fluent peers. These weaknesses are likely due, in part, to differences in phonological and, perhaps, semantic processing of words to aid memory.

Use of a phoneme monitoring task to examine lexical access in adults who do and do not stutter

Previous work has postulated that a deficit in lexicalization may be an underlying cause of a stuttering disorder (Prins, Main, & Wampler, 1997; Wingate, 1988). This study investigates the time course of lexicalization of nouns and verbs in adults who stutter. A generalized phoneme monitoring (PM) paradigm was used. Adults who stutter (AWS) and typically-fluent peers both showed an expected effect of word class (verbs yielded slower and less accurate monitoring than nouns), as well as phoneme position (word medial/final phonemes yielded slower and less accurate monitoring than word initial phonemes). However, AWS had considerably more difficulty when targets to be monitored were embedded in the medial position. A negative correlation between speed and accuracy was found in typically fluent adults, but not in AWS. AWS also scored nonsignificantly more poorly on an experimental language task. Because of the additional difficulty noted in AWS with word-medial targets, our results provide evidence of phonological encoding differences between the two groups. Expanded use of the PM paradigm is recommended for the exploration of additional aspects of language processing in people who stutter.

Short-Term Memory, Inhibition, and Attention in Developmental Stuttering: A Meta-Analysis

Purpose

This study presents a meta-analytic review of differences in verbal short-term memory, inhibition, and attention between children who stutter (CWS) and children who do not stutter (CWNS).

Method

Electronic databases and reference sections of articles were searched for candidate studies that examined verbal short-term memory, inhibition, and attention using behavioral and/or parent report measures. Twenty-nine studies met the eligibility criteria, which included, among other things, children between the ages of 3 and 18 years and the availability of quantitative data for effect size calculations. Data were extracted, coded, and analyzed, with the magnitude of the difference between the 2 groups of children being estimated using Hedge's g (Hedges & Olkin, 1985).

Results

Based on the random-effects model (Hunter & Schmidt, 2004), findings revealed that CWS scored lower than CWNS on measures of nonword repetition (Hedges' g = -0.62), particularly at lengths of 2 and 3 syllables (Hedges' g = -0.62 and - 0.50, respectively), and forward span (Hedges' g = -0.40). Analyses further revealed that the parents of CWS rated their children as having weaker inhibition (Hedges' g = -0.44) and attentional focus/persistence (Hedges' g = -0.36) skills than the parents of CWNS, but there were no significant differences between CWS and CWNS in behavioral measures of inhibition and attention.

Conclusion

The present findings were taken to suggest that cognitive processes are important variables associated with developmental stuttering.

Using Language-Specific and Bilingual Measures to Explore Lexical-Grammatical Links in Young Latino Dual-Language Learners

Purpose

This study examined the nature of the relation between language-specific vocabulary and conceptual lexical-semantic skills with grammatical abilities within and across languages in preschool Latino dual language learners (DLLs).

Method

Sixty-one typically developing, Spanish-English speaking DLLs from preschools serving low-income families participated in the study. Lexical, semantic, and grammar skills were assessed toward the end of the fall in both Spanish and English using normative and researcher-developed assessment instruments. Hierarchical linear regressions using baseline cross-sectional data were completed to determine the association of language-specific vocabulary and bilingual lexical and semantic abilities to grammatical skills measured by sentence repetition tasks in Spanish and English both within and across languages.

Results

Results from the study revealed that a considerable percentage of the variance in the grammatical ability of these Latino DLL preschoolers in both Spanish and English was explained by lexical variables in the same language (54% in English and 16% in Spanish). In the strong language (Spanish), bilingual semantic skills also played a role, explaining an additional 8% of the variance. Conceptual vocabulary was a significant predictor of English grammar in the model that excluded the language-specific vocabulary measures.

Conclusions

These findings suggest that grammatical skills in the Latino preschoolers examined in the study are strongly related to language-specific measures of vocabulary. In contrast, no evidence supporting the relation between vocabulary and grammar skills across languages was observed. Findings from this study provide insight into the impact of bilingual lexical-semantic knowledge on the grammatical skills of dual-language preschool children developing language abilities in their 2 languages. Clinical implications are also discussed.

Neural Indices of Semantic Processing in Early Childhood Distinguish Eventual Stuttering Persistence and Recovery

Purpose

Maturation of neural processes for language may lag in some children who stutter (CWS), and event-related potentials (ERPs) distinguish CWS who have recovered from those who have persisted. The current study explores whether ERPs indexing semantic processing may distinguish children who will eventually persist in stuttering (CWS-ePersisted) from those who will recover from stuttering (CWS-eRecovered).

Method

Fifty-six 5-year-old children with normal receptive language listened to naturally spoken sentences in a story context. ERP components elicited for semantic processing (N400, late positive component [LPC]) were compared for CWS-ePersisted, CWS-eRecovered, and children who do not stutter (CWNS).

Results

The N400 elicited by semantic violations had a more focal scalp distribution (left lateralized and less anterior) in the CWS-eRecovered compared with CWS-ePersisted. Although the LPC elicited in CWS-eRecovered and CWNS did not differ, the LPC elicited in the CWS-ePersisted was smaller in amplitude compared with that in CWNS.

Conclusions

ERPs elicited in 5-year-old CWS-eRecovered compared with CWS-ePersisted suggest that future recovery from stuttering may be associated with earlier maturation of semantic processes in the preschool years. Subtle differences in ERP indices offer a window into neural maturation processes for language and may help distinguish the course of stuttering development.

The History of Stuttering by 7 Years of Age: Follow-Up of a Prospective Community Cohort

PURPOSE

For a community cohort of children confirmed to have stuttered by the age of 4 years, we report (a) the recovery rate from stuttering, (b) predictors of recovery, and (c) comorbidities at the age of 7 years.

METHOD

This study was nested in the Early Language in Victoria Study. Predictors of stuttering recovery included child, family, and environmental measures and first-degree relative history of stuttering. Comorbidities examined at 7 years included temperament, language, nonverbal cognition, and health-related quality of life.

RESULTS

The recovery rate by the age of 7 years was 65%. Girls with stronger communication skills at the age of 2 years had higher odds of recovery (adjusted OR = 7.1, 95% CI [1.3, 37.9], p = .02), but similar effects were not evident for boys (adjusted OR = 0.5, 95% CI [0.3, 1.1], p = .10). At the age of 7 years, children who had recovered from stuttering were more likely to have stronger language skills than children whose stuttering persisted (p = .05). No evident differences were identified on other outcomes including nonverbal cognition, temperament, and parent-reported quality of life.

CONCLUSION

Overall, findings suggested that there may be associations between language ability and recovery from stuttering. Subsequent research is needed to explore the directionality of this relationship.

Explicit and Implicit Verbal Response Inhibition in Preschool-Age Children Who Stutter

PURPOSE

The purpose of this study was to examine (a) explicit and implicit verbal response inhibition in preschool children who do stutter (CWS) and do not stutter (CWNS) and (b) the relationship between response inhibition and language skills.

METHOD

Participants were 41 CWS and 41 CWNS between the ages of 3;1 and 6;1 (years;months). Explicit verbal response inhibition was measured using a computerized version of the grass-snow task (Carlson & Moses, 2001), and implicit verbal response inhibition was measured using the baa-meow task. Main dependent variables were reaction time and accuracy.

RESULTS

The CWS were significantly less accurate than the CWNS on the implicit task, but not the explicit task. The CWS also exhibited slower reaction times than the CWNS on both tasks. Between-group differences in performance could not be attributed to working memory demands. Overall, children's performance on the inhibition tasks corresponded with parents' perceptions of their children's inhibition skills in daily life.

CONCLUSIONS

CWS are less effective and efficient than CWNS in suppressing a dominant response while executing a conflicting response in the verbal domain.

Evidence-Based Multifactorial Assessment of Preschool-Age Children Who Stutter

This review summarizes extant findings supporting multifactorial models of stuttering within the context of preschool-age stuttering assessment. Evidence is given for a number of speech-language and associated factors/domains to consider when evaluating young children who stutter. Selected factors are presented in two parts: (1) Caregiver Interview and (2) Direct Child Assessment. Factors addressed during caregiver interviews include: gender, time since and age at stuttering onset, family history of stuttering, caregivers' perception/concerns about stuttering, and temperament. Factors addressed during direct child assessments include: stuttering behaviors, speech-associated attitudes/awareness, and speech rate, as well as speech sound and language development. Interactions/relations among factors are noted, showing their combined effects and contributions to childhood stuttering. Additionally, suggested clinical applications are provided wherever appropriate. Such evidence and practical applications bridge the gap between theory and clinical practice, thus advancing the abilities of speech-language pathologists to conduct well-informed, comprehensive stuttering evaluations.

Relationship between Speech Production and Perception in People Who Stutter

Speech production difficulties are apparent in people who stutter (PWS). PWS also have difficulties in speech perception compared to controls. It is unclear whether the speech perception difficulties in PWS are independent of, or related to, their speech production difficulties. To investigate this issue, functional MRI data were collected on 13 PWS and 13 controls whilst the participants performed a speech production task and a speech perception task. PWS performed poorer than controls in the perception task and the poorer performance was associated with a functional activity difference in the left anterior insula (part of the speech motor area) compared to controls. PWS also showed a functional activity difference in this and the surrounding area [left inferior frontal cortex (IFC)/anterior insula] in the production task compared to controls. Conjunction analysis showed that the functional activity differences between PWS and controls in the left IFC/anterior insula coincided across the perception and production tasks. Furthermore, Granger Causality Analysis on the resting-state fMRI data of the participants showed that the causal connection from the left IFC/anterior insula to an area in the left primary auditory cortex (Heschl's gyrus) differed significantly between PWS and controls. The strength of this connection correlated significantly with performance in the perception task. These results suggest that speech perception difficulties in PWS are associated with anomalous functional activity in the speech motor area, and the altered functional connectivity from this area to the auditory area plays a role in the speech perception difficulties of PWS.

Dissociations among linguistic, cognitive, and auditory-motor neuroanatomical domains in children who stutter

The onset of developmental stuttering typically occurs between 2 to 4 years of age, coinciding with a period of rapid development in speech, language, motor and cognitive domains. Previous studies have reported generally poorer performance and uneven, or "dissociated" development across speech and language domains in children who stutter (CWS) relative to children who do not stutter (CWNS) (Anderson, Pellowski, & Conture, 2005). The aim of this study was to replicate and expand previous findings by examining whether CWS exhibit dissociated development across speech-language, cognitive, and motor domains that are also reflected in measures of neuroanatomical development. Participants were 66CWS (23 females) and 53CWNS (26 females) ranging from 3 to 10 years. Standardized speech, language, cognitive, and motor skills measures, and fractional anisotropy (FA) values derived from diffusion tensor imaging from speech relevant "dorsal auditory" left perisylvian areas (Hickok & Poeppel, 2007) were analyzed using a correlation-based statistical procedure (Coulter, Anderson, & Conture, 2009) that quantified dissociations across domains. Overall, CWS scored consistently lower on speech, language, cognitive and motor measures, and exhibited dissociated development involving these same measures and white matter neuroanatomical indices relative to CWNS. Boys who stutter exhibited a greater number of dissociations compared to girls who stutter. Results suggest a subgroup of CWS may have incongruent development across multiple domains, and the resolution of this imbalance may be a factor in recovery from stuttering.

Speech-Language Dissociations, Distractibility, and Childhood Stuttering

PURPOSE

This study investigated the relation among speech-language dissociations, attentional distractibility, and childhood stuttering.

METHOD

Participants were 82 preschool-age children who stutter (CWS) and 120 who do not stutter (CWNS). Correlation-based statistics (Bates, Appelbaum, Salcedo, Saygin, & Pizzamiglio, 2003) identified dissociations across 5 norm-based speech-language subtests. The Behavioral Style Questionnaire Distractibility subscale measured attentional distractibility. Analyses addressed (a) between-groups differences in the number of children exhibiting speech-language dissociations; (b) between-groups distractibility differences; (c) the relation between distractibility and speech-language dissociations; and (d) whether interactions between distractibility and dissociations predicted the frequency of total, stuttered, and nonstuttered disfluencies.

RESULTS

More preschool-age CWS exhibited speech-language dissociations compared with CWNS, and more boys exhibited dissociations compared with girls. In addition, male CWS were less distractible than female CWS and female CWNS. For CWS, but not CWNS, less distractibility (i.e., greater attention) was associated with more speech-language dissociations. Last, interactions between distractibility and dissociations did not predict speech disfluencies in CWS or CWNS.

CONCLUSIONS

The present findings suggest that for preschool-age CWS, attentional processes are associated with speech-language dissociations. Future investigations are warranted to better understand the directionality of effect of this association (e.g., inefficient attentional processes → speech-language dissociations vs. inefficient attentional processes ← speech-language dissociations).

Neurodevelopment for syntactic processing distinguishes childhood stuttering recovery versus persistence

BACKGROUND

Characterized by the presence of involuntary speech disfluencies, developmental stuttering is a neurodevelopmental disorder of atypical speech-motor coordination. Although the etiology of stuttering is multifactorial, language development during early childhood may influence both the onset of the disorder and the likelihood of recovery. The purpose of this study was to determine whether differences in neural indices mediating language processing are associated with persistence or recovery in school-age children who stutter.

METHODS

Event-related brain potentials (ERPs) were obtained from 31 6-7-year-olds, including nine children who do not stutter (CWNS), 11 children who had recovered from stuttering (CWS-Rec), and 11 children who persisted in stuttering (CWS-Per), matched for age, and all with similar socioeconomic status, nonverbal intelligence, and language ability. We examined ERPs elicited by semantic and syntactic (phrase structure) violations within an auditory narrative consisting of English and Jabberwocky sentences. In Jabberwocky sentences, content words were replaced with pseudowords to limit semantic context. A mixed effects repeated measures analysis of variance (ANOVA) was computed for ERP components with four within-subject factors, including condition, hemisphere, anterior/posterior distribution, and laterality.

RESULTS

During the comprehension of English sentences, ERP activity mediating semantic and syntactic (phrase structure) processing did not distinguish CWS-Per, CWS-Rec, and CWNS. Semantic violations elicited a qualitatively similar N400 component across groups. Phrase structure violations within English sentences also elicited a similar P600 component in all groups. However, identical phrase structure violations within Jabberwocky sentences elicited a P600 in CWNS and CWS-Rec, but an N400-like effect in CWS-Per.

CONCLUSIONS

The distinguishing neural patterns mediating syntactic, but not semantic, processing provide evidence that specific brain functions for some aspects of language processing may be associated with stuttering persistence. Unlike CWS-Rec and CWNS, the lack of semantic context in Jabberwocky sentences seemed to affect the syntactic processing strategies of CWS-Per, resulting in the elicitation of semantically based N400-like activity during syntactic (phrase structure) violations. This vulnerability suggests neural mechanisms associated with the processing of syntactic structure may be less mature in 6-7-year-old children whose stuttering persisted compared to their fluent or recovered peers.

Lexical and phonological processing in visual word recognition by stuttering children: evidence from Spanish

A number of studies have pointed out that stuttering-like disfluencies could be the result of failures in central and linguistic processing. The goal of the present paper is to analyze if stuttering implies deficits in the lexical and phonological processing in visual word recognition. This study compares the performance of 28 children with and without stuttering in a standard lexical decision task in a transparent orthography: Spanish. Word frequency and syllable frequency were manipulated in the experimental words. Stutterers were found to be considerably slower (in their correct responses) and produced more errors than the non- stutterers (χ(1) = 36.63, p < .001, η2 = .60). There was also a facilitation effect of syllable frequency, restricted to low frequency words and only in the stutterers group (t1(10) = 3.67, p < .005; t2(36) = 3.10, p < .001). These outcomes appear to suggest that the decoding process of stutterers exhibits a deficit in the interface between the phonological-syllabic level and the word level.

Real-time processing in picture naming in adults who stutter: ERP evidence

OBJECTIVE

The aim was to compare real-time language/cognitive processing in picture naming in adults who stutter (AWS) versus typically-fluent adults (TFA).

METHODS

Participants named pictures preceded by masked prime words. Primes and target picture labels were identical or mismatched. Priming effects on naming and picture-elicited ERP activity were analyzed. Vocabulary knowledge correlations with these measures were assessed.

RESULTS

Priming improved naming RTs and accuracy in both groups. RTs were longer for AWS, and correlated positively with receptive vocabulary in TFA. Electrophysiologically, posterior-P1 amplitude negatively correlated with expressive vocabulary in TFA versus receptive vocabulary in AWS. Frontal/temporal-P1 amplitude correlated positively with expressive vocabulary in AWS. Identity priming enhanced frontal/posterior-N2 amplitude in both groups, and attenuated P280 amplitude in AWS. N400 priming was topographically-restricted in AWS.

CONCLUSIONS

Results suggest that conceptual knowledge was perceptually-grounded in expressive vocabulary in TFA versus receptive vocabulary in AWS. Poorer expressive vocabulary in AWS was potentially associated with greater suppression of irrelevant conceptual information. Priming enhanced N2-indexed cognitive control and visual attention in both groups. P280-indexed focal attention attenuated with priming in AWS only. Topographically-restricted N400 priming suggests that lemma/word form connections were weaker in AWS.

SIGNIFICANCE

Real-time language/cognitive processing in picture naming operates differently in AWS.

Emotional reactivity and regulation associated with fluent and stuttered utterances of preschool-age children who stutter

PURPOSE

The purpose of this study was to assess the relation between emotional reactivity and regulation associated with fluent and stuttered utterances of preschool-age children who stutter (CWS) and those who do not (CWNS).

PARTICIPANTS

Participants were eight 3 to 6-year old CWS and eight CWNS of comparable age and gender.

METHODS

Participants were exposed to three emotion-inducing overheard conversations--neutral, angry and happy--and produced a narrative following each overheard conversation. From audio-video recordings of these narratives, coded behavioral analysis of participants' negative and positive affect and emotion regulation associated with stuttered and fluent utterances was conducted.

RESULTS

Results indicated that CWS were significantly more likely to exhibit emotion regulation attempts prior to and during their fluent utterances following the happy as compared to the negative condition, whereas CWNS displayed the opposite pattern. Within-group assessment indicated that CWS were significantly more likely to display negative emotion prior to and during their stuttered than fluent utterances, particularly following the positive overheard conversation.

CONCLUSIONS

After exposure to emotional-inducing overheard conversations, changes in preschool-age CWS's emotion and emotion regulatory attempts were associated with the fluency of their utterances.

LEARNING OUTCOMES

After reading this article, the reader will be able to: (1) describe various measures of emotional reactivity and regulation, including parent-based reports and behavioral coding, and how they may contribute to childhood stuttering; (2) explain emotional differences between the stuttered and fluent utterances of CWS and CWNS; and (3) discuss how emotions may contribute to CWS' instances of stuttering.

Lexical priming in fluent and with developmental stuttering children

PURPOSE

To examine the possible relationship between lexical variables (categorization and naming) and developmental stuttering.

METHODS

Thirty Brazilian Portuguese speaking children with ages ranging from 7 to 9 years and 11 months participated in the study. We applied a lexical priming paradigm to experimentally investigate whether children with developmental stuttering (Research Group) differed from their fluent peers (Control Group), with respect to reaction time in three conditions - control (without prime); semantically related prime, and semantically independent prime - of two experimental tasks: categorization and naming of the target stimulus.

RESULTS

No difference between groups was observed in reaction time on the categorization task. However, there was a condition effect showing that, for both groups, reaction time was shorter in the semantically related prime condition when compared to the no prime condition. In the naming task, a between-group difference was observed in reaction time, indicating a longer reaction time in the Research Group than the Control Group. There was no condition effect on naming, i.e. the Research Group showed slower reaction time regardless of prime type.

CONCLUSIONS

The results confirm the hypothesis that, in children with developmental stuttering, readiness in motor programming of speech is slowed when compared to fluent children. There is no difference between groups when the lexical function does not require speech readiness.

Speech sound articulation abilities of preschool-age children who stutter

PURPOSE

The purpose of this study was to assess the association between speech sound articulation and childhood stuttering in a relatively large sample of preschool-age children who do and do not stutter, using the Goldman-Fristoe Test of Articulation-2 (GFTA-2; Goldman & Fristoe, 2000).

METHOD

Participants included 277 preschool-age children who do (CWS; n=128, 101 males) and do not stutter (CWNS; n=149, 76 males). Generalized estimating equations (GEE) were performed to assess between-group (CWS versus CWNS) differences on the GFTA-2. Additionally, within-group correlations were performed to explore the relation between CWS' speech sound articulation abilities and their stuttering frequency and severity, as well as their sound prolongation index (SPI; Schwartz & Conture, 1988).

RESULTS

No significant differences were found between the articulation scores of preschool-age CWS and CWNS. However, there was a small gender effect for the 5-year-old age group, with girls generally exhibiting better articulation scores than boys. Additional findings indicated no relation between CWS' speech sound articulation abilities and their stuttering frequency, severity, or SPI.

CONCLUSIONS

Findings suggest no apparent association between speech sound articulation-as measured by one standardized assessment (GFTA-2)-and childhood stuttering for this sample of preschool-age children (N=277).

EDUCATIONAL OBJECTIVES

After reading this article, the reader will be able to: (1) discuss salient issues in the articulation literature relative to children who stutter; (2) compare/contrast the present study's methodologies and main findings to those of previous studies that investigated the association between childhood stuttering and speech sound articulation; (3) identify future research needs relative to the association between childhood stuttering and speech sound development; (4) replicate the present study's methodology to expand this body of knowledge.

Early childhood stuttering and electrophysiological indices of language processing

We examined neural activity mediating semantic and syntactic processing in 27 preschool-age children who stutter (CWS) and 27 preschool-age children who do not stutter (CWNS) matched for age, nonverbal IQ and language abilities. All participants displayed language abilities and nonverbal IQ within the normal range. Event-related brain potentials (ERPs) were elicited while participants watched a cartoon video and heard naturally spoken sentences that were either correct or contained semantic or syntactic (phrase structure) violations. ERPs in CWS, compared to CWNS, were characterized by longer N400 peak latencies elicited by semantic processing. In the CWS, syntactic violations elicited greater negative amplitudes for the early time window (150-350 ms) over medial sites compared to CWNS. Additionally, the amplitude of the P600 elicited by syntactic violations relative to control words was significant over the left hemisphere for the CWNS but showed the reverse pattern in CWS, a robust effect only over the right hemisphere. Both groups of preschoolage children demonstrated marked and differential effects for neural processes elicited by semantic and phrase structure violations; however, a significant proportion of young CWS exhibit differences in the neural functions mediating language processing compared to CWNS despite normal language abilities. These results are the first to show that differences in event-related brain potentials reflecting language processing occur as early as the preschool years in CWS and provide the first evidence that atypical lateralization of hemispheric speech/language functions previously observed in the brains of adults who stutter begin to emerge near the onset of developmental stuttering.

EDUCATIONAL OBJECTIVES

The reader will be able to: (1) describe the role of language processing in current theoretical models of developmental stuttering; (2) summarize current evidence regarding language processing differences between individuals who do and do not stutter; (3) describe typical changes in neural indices of semantic and syntactic processing across development; (4) discuss the potential implications of the current findings in relation to theories of developmental stuttering.

Effects of sentence-structure complexity on speech initiation time and disfluency

There is general agreement that stuttering is caused by a variety of factors, and language formulation and speech motor control are two important factors that have been implicated in previous research, yet the exact nature of their effects is still not well understood. Our goal was to test the hypothesis that sentences of high structural complexity would incur greater processing costs than sentences of low structural complexity and these costs would be higher for adults who stutter than for adults who do not stutter. Fluent adults and adults who stutter participated in an experiment that required memorization of a sentence classified as low or high structural complexity followed by production of that sentence upon a visual cue. Both groups of speakers initiated most sentences significantly faster in the low structural complexity condition than in the high structural complexity condition. Adults who stutter were over-all slower in speech initiation than were fluent speakers, but there were no significant interactions between complexity and group. However, adults who stutter produced significantly more disfluencies in sentences of high structural complexity than in those of low complexity.

EDUCATIONAL OBJECTIVES

After reading this article, the learner will be able to: (a) identify integral parts of all well-known models of adult sentence production; (b) summarize the way that sentence structure might negatively influence the speech production processes; (c) discuss whether sentence structure influences speech initiation time and disfluencies.

Past tense marking in the spontaneous speech of preschool children who do and do not stutter

PURPOSE

The aim of this study was to identify whether different patterns of errors exist in irregular past-tense verbs in children who stutter (CWS) and children who do not stutter (CWNS).

METHOD

Spontaneous language samples of thirty-one age- and gender-matched pairs of children (total N=62) between the ages of 24 months and 59 months were analyzed.

RESULTS

Results indicated that children who do and do not stutter over-regularize irregular past-tense verbs (i.e., saying runned for ran) with comparable frequency. However, two nonsignificant trends which suggest possible intra-group differences were noted. First, irregular past tense verbs represented a greater portion of total verbs for CWS than for CWNS. Second, CWS appeared to double-mark (i.e., say ranned for ran) more often than CWNS. Results are discussed in light of theories about the acquisition of the irregular past-tense and about differences in language skills between CWS and CWNS.

EDUCATIONAL OBJECTIVES

After reading this article, the reader will be able to: (a) summarize previous findings about connections between stuttering and language in CWS and CWNS; (b) describe similarities and differences between irregular past-tense verb use and errors in CWS and CWNS; (c) discuss possible connections between the declarative-procedural model and stuttering.

The effects of concurrent cognitive load on phonological processing in adults who stutter

PURPOSE

To determine whether phonological processing in adults who stutter (AWS) is disrupted by increased amounts of cognitive load in a concurrent attention-demanding task.

METHOD

Nine AWS and 9 adults who do not stutter (AWNS) participated. Using a dual-task paradigm, the authors presented word pairs for rhyme judgments and, concurrently, letter strings for memory recall. The rhyme judgment task manipulated rhyming type (rhyming/nonrhyming) and orthographic representation (similar/dissimilar). The memory recall task varied stimulus complexity (no letters, 3 letters, 5 letters). Rhyme judgment accuracy and reaction time (RT) were used to assess phonological processing, and letter recall accuracy was used to measure memory recall.

RESULTS

For rhyme judgments, AWS were as accurate as AWNS, and the increase in the cognitive load did not affect rhyme judgment accuracy of either group. Significant group differences were found in RTs (delays by AWS were 241 ms greater). RTs of AWS were also slower in the most demanding rhyme condition and varied with the complexity of the memory task. Accuracy of letter recall of AWS was comparatively worse in the most demanding 5-letter condition.

CONCLUSION

Phonological and cognitive processing of AWS is more vulnerable to disruptions caused by increased amounts of cognitive load in concurrent attention-demanding tasks.

Effect of onset and rhyme primes in preschoolers with typical development and specific language impairment

PURPOSE

In this study, the authors used cued shadowing to examine children's phonological word-form representations by studying the effects of onset and rhyme primes on lexical access.

METHOD

Twenty-five preschoolers with specific language impairment (SLI; hereafter known as the SLI group), 24 age- and gender-matched children (AM group), and 20 vocabulary- and gender-matched children (VM group) participated. Children listened to pairs of words and repeated the second word as quickly as they could. Primes included words with overlapping onsets, words with overlapping rimes, and identical or unrelated words.

RESULTS

As expected, unrelated words inhibited production in the AM and VM groups. Overlapping rimes primed production in the AM group. No inhibitory or priming effects were found for the SLI group.

CONCLUSION

Phonological priming may be used to study the phonological representations of preschool-age children. Results suggest that none of the groups accessed words incrementally. Priming for overlapping rimes by the AM but not the VM or SLI groups may indicate that the AM group benefited from lexical organization favoring nucleus + rime organization that has not yet developed for the VM or SLI groups. The lack of inhibition in the SLI group suggests that their phonological representations were not detailed enough to prime words in their lexicon or that they did not process the prime or target words.

Language abilities of children who stutter: a meta-analytical review

PURPOSE

To identify, integrate, and summarize evidence from empirical studies of the language abilities of children who stutter (CWS) and children who do not stutter (CWNS).

METHOD

Candidate studies were identified through electronic databases, the tables of contents of speech-language journals, and reference lists of relevant articles and literature reviews. The 22 included studies met the following criteria: studied both children who did and did not stutter between ages 2;0 (years;months) and 8;0, and reported norm-referenced language measures and/or measures from spontaneous language samples amenable to effect size calculation. Data were extracted using a coding manual and were assessed by application of general and specialized analytical software. Mean difference effect size was estimated using Hedges's g (Hedges, 1982).

RESULTS

Findings indicated that CWS scored significantly lower than CWNS on norm-referenced measures of overall language (Hedges's g = -0.48), receptive (Hedges's g = -0.52) and expressive vocabulary (Hedges's g = -0.41), and mean length of utterance (Hedges's g = -0.23).

CONCLUSIONS

Present findings were taken to suggest that children's language abilities are potentially influential variables associated with childhood stuttering.

Emotional reactivity, regulation and childhood stuttering: a behavioral and electrophysiological study

The purpose of this preliminary study was to assess whether behavioral and psychophysiological correlates of emotional reactivity and regulation are associated with developmental stuttering, as well as determine the feasibility of these methods in preschool-age children. Nine preschool-age children who stutter (CWS) and nine preschool-age children who do not stutter (CWNS) listened to brief background conversations conveying happy, neutral, and angry emotions (a resolution conversation followed the angry conversation), then produced narratives based on a text-free storybook. Electroencephalograms (EEG) recorded during listening examined cortical correlates of emotional reactivity and regulation. Speech disfluencies and observed emotion regulation were measured during a narrative immediately after each background conversation. Results indicated that decreased use of regulatory strategies is related to more stuttering in children who stutter. However, no significant differences were found in EEG measurements of emotional reactivity and regulation between CWS and CWNS or between emotion elicitation conditions. Findings were taken to suggest that use of regulatory strategies may relate to the fluency of preschool-age children's speech-language output.

LEARNING OUTCOMES

The reader will be able to (1) describe emotional reactivity and regulation processes, (2) discuss evidence for or against the relations of emotional reactivity, regulation and stuttering, (3) understand how multiple measures can be used to measure emotional reactivity and regulation.

Investigating the inner speech of people who stutter: evidence for (and against) the covert repair hypothesis

In their Covert Repair Hypothesis, Postma and Kolk (1993) suggest that people who stutter make greater numbers of phonological encoding errors, which are detected during the monitoring of inner speech and repaired, with stuttering-like disfluencies as a consequence. Here, we report an experiment that documents the frequency with which such errors are made. Thirty-two people who stutter (PWS) and thirty-two normally fluent controls, matched for age, gender and education, recited tonguetwisters and self-reported any errors they perceived themselves to have made. In 50% of trials the tonguetwisters were recited silently and errors reported were those detected in inner speech. Compared to controls, PWS produced significantly more word-onset and word-order errors. Crucially, this difference was found in inner as well as in overt speech. Comparison of experimenter ratings and participants' own self-ratings of their overt speech revealed similar levels of accuracy across the two groups, ruling out a suggestion that PWS were simply more sensitive to the errors they made. However, the frequency of participants' inner-speech errors was not correlated to their SSI4 scores, nor to two other measures of stuttering severity. Our findings support Postma and Kolk's contention that, when speech rate is held constant, PWS make, and therefore detect, more errors of phonological encoding. They do not, however, support the hypothesis that stuttering-like disfluencies in everyday speech stem from covert repairs of errors of phonological encoding.

LEARNING OUTCOMES

Readers will learn about three current psycholinguistic theories of stuttering, and how speech-errors elicited during tonguetwister recitation can be used to explore the controversies that exist surrounding: (a) Whether or not people who stutter are more prone to making language production errors; and (b) The extent to which stuttering-like disfluencies stem from covert repairs of language-production errors.

Relationships among linguistic processing speed, phonological working memory, and attention in children who stutter

Relatively recently, experimental studies of linguistic processing speed in children who stutter (CWS) have emerged, some of which suggest differences in performance among CWS compared to children who do not stutter (CWNS). What is not yet well understood is the extent to which underlying cognitive skills may impact performance on timed tasks of linguistic performance. The purpose of this study was to explore possible relationships between measures of linguistic processing speed and two aspects of cognition: phonological working memory and attention. Participants were 9 CWS and 14 CWNS between the ages of 3;6 and 5;2. Children participated in a computerized picture naming task (an index of linguistic processing speed) and a nonword repetition task (an index of phonological working memory). Parents completed a temperament behavior questionnaire, from which information about the children's attentional skills was collected. Findings revealed that the groups did not differ from each other on speed of picture naming or attention; however, the CWS performed significantly worse in nonword repetition. In addition, after partialling out the effects of age, (a) for CWS only, there was a significant negative relationship between picture naming speed and nonword repetition; (b) there were no significant relationships for either group between aspects of attention and picture naming speed; and (c) only the CWNS showed a significant relationship between nonword repetition and focused attentional skills. These results underscore the need to consider the underlying skills associated with lexically related aspects of language production when examining the task performances of CWS and CWNS.

EDUCATIONAL OBJECTIVES

The reader will be able to: (a) summarize findings from previous studies examining the speech and language performance of children who do (CWS) and do not stutter (CWNS); (b) describe findings of previous studies related to nonword repetition and attention in CWS; (c) compare the results of the present study with previous work in this area; and (d) discuss speculations concerning the relationship between linguistic processing speed, phonological working memory, and attention in CWS and CWNS.

Effects of word frequency and phonological neighborhood characteristics on confrontation naming in children who stutter and normally fluent peers

In a prior study (Newman & Bernstein Ratner, 2007), we examined the effects of word frequency and phonological neighborhood characteristics on confrontation naming latency, accuracy and fluency in adults who stutter and typically fluent speakers. A small difference in accuracy favoring fluent adults was noted, but no other patterns differentiated fluent speaker responses from those obtained from the adults who stutter. Because lexical organization or retrieval differences might be more easily observed in less mature language users, we replicated the experiment using 15 children who stutter (ages 4;10 16;2) and age- and gender-matched peers. Results replicated the earlier study: the two groups of participants showed strikingly similar patterns of responses based on word frequency and neighborhood characteristics. There were also no differences in naming accuracy overall between the two groups. Given our results and those of other researchers who have explored the impact of neighborhood variables on lexical retrieval in people who stutter, we suggest that differences between language production in PWS and fluent speakers are not likely to involve atypical phonological organization of lexical neighborhoods.

EDUCATIONAL OBJECTIVES

After reading this article, the reader will be able to: (1) define and illustrate words that have differing frequency and phonological neighborhood characteristics; (2) evaluate whether or not children who stutter appear to organize their mental lexicons differently than those of children who are typically fluent; (3) suggest future areas of research into language processing in people who stutter.

Childhood stuttering and dissociations across linguistic domains: a replication and extension

The purpose of this investigation was to replicate the methods of Anderson, Pellowski, and Conture (2005) to determine whether a different sample of preschool children who stutter (CWS) exhibit more dissociations in speech-language abilities than children who do not stutter (CWNS; Study 1) and to examine the relation between dissociations and specific characteristics of stuttering (e.g., most common disfluency type) using a much larger sample size (Study 2). Participants for Study 1 were 40 CWS and 40 CWNS between the ages of 3;0 and 5;11. Participants for Study 2 were the same as for Study 1 plus the 45 CWS and 45 CWNS used by Anderson et al. (2005) for a total of 85 CWS and 85 CWNS. Participants were administered five standardized speech-language (sub)tests and a conversational speech sample was obtained from each participant for the analyses of speech disfluencies/stuttering. Standard scores from the standardized speech-language tests were analyzed using a correlation-based statistical procedure (Bates, Applebaum, Sacedo, Saygin, & Pizzamiglio, 2003) to identify possible dissociations among the speech-language measures. Findings from Study 1 supported Anderson et al.'s findings that CWS exhibited significantly more speech-language dissociations than CWNS. Results from Study 2 further revealed that CWS who exhibited dissociations were more likely to exhibit non-stuttered (other) disfluencies as their most common disfluency type. Findings provide further support for the possibility that dissociations among various aspects of the speech-language system may contribute to the difficulties that some children have establishing normally fluent speech.

EDUCATIONAL OBJECTIVES

The reader will be able to: (a) summarize findings from previous studies examining the speech and language performance of children who do and do not stutter; (b) describe the concept of "dissociations" in the speech and language skills of young children; (c) compare the results of the present study with previous work in this area; and (d) discuss speculations concerning the manner in which dissociations might affect fluency development in children who stutter.

Effects of syntactic complexity and sentence-structure priming on speech initiation time in adults who stutter

PURPOSE

To test the hypotheses that adults who stutter will be slower in producing syntactically complex sentences than fluent adults and will benefit more from sentence-structure priming than will fluent adults.

METHOD

Adults who stutter (n = 15) and fluent adults (n = 15) participated in 2 experiments. In Experiment 1, adults in both groups were administered a task that required memorization and production of sentences that varied in syntactic complexity. The same individuals who participated in Experiment 1 also participated in Experiment 2. The second experiment required all participants to create and produce sentences under primed and unprimed sentence-structure conditions.

RESULTS

Relative to adults who do not stutter, the speech initiation time of fluent utterances of adults who stutter became increasingly slower as syntactic complexity increased, and they exhibited greater facilitative effects of sentence-structure priming. In addition, adults who stutter showed a significant correlation between syntactic complexity and priming facilitation.

CONCLUSION

Data from these experiments confirmed both hypotheses and provided evidence that a subgroup of adults who stutter have grammatical encoding differences when compared with adults who do not stutter.

Sentence position and syntactic complexity of stuttering in early childhood: a longitudinal study

The purpose of the present investigation was to assess longitudinal word- and sentence-level measures of stuttering in young children. Participants included 12 stuttering and non-stuttering children between 36 and 71 months of age at an initial visit who exhibited a range of stuttering rates. Parent-child spontaneous speech samples were obtained over a period of two years at six-month intervals. Each speech sample was transcribed, and both stuttering-like disfluencies (SLDs) and other disfluencies (ODs) were coded. Word- and sentence-level measures of SLDs were used to assess linguistic characteristics of stuttering. Results of the word-level analysis indicated that stuttering was most likely to occur at the sentence-initial position, and that a tendency to stutter on function words was present only at the sentence-initial position. Results of the sentence-level analyses indicated that sentences containing ODs and those containing SLDs were both significantly longer and more complex than fluent sentences, but did not differ from each other. Word- and sentence-level measures also did not change across visits. Results were taken to suggest that both SLDs and ODs originate during the same stage of sentence planning.

EDUCATIONAL OBJECTIVES

The reader will be able to: (1) describe the importance of sentence position in the occurrence of speech disfluencies, (2) describe the relation between sentence complexity and the occurrence of speech disfluencies, and (3) describe the potential role of different aspects of sentence planning on the occurrence of speech disfluencies.

Lexical priming of function words and content words with children who do, and do not, stutter

The specific mechanisms that underlie childhood stuttering are not fully understood. The current study investigated these mechanisms by comparing the effect on fluency of priming different components of a short sentence. The main findings were that: (1) both children who stutter (CWS) (n=12, M age=6;3) and children who do not stutter (CWNS) (n=12, M age=6;6) were more fluent after function word (FW) priming than content word (CW) priming, (2) this effect was significantly greater for CWS than for CWNS, and (3) after FW priming, CWS produced CWs with significantly longer duration than did CWNS. These findings are discussed in relation to two competing theories of stuttering: the covert repair hypothesis (CRH) [Kolk, H., & Postma, A. (1997). Stuttering as a covert repair phenomenon. In R. F. Curlee & G. M. Siegel (Eds.), Nature and treatments of stuttering: New directions (pp. 182-203). Needham Heights, MA: Allyn & Bacon] and the developmentally focused model of Howell and Au-Yeung [Howell, P., & Au-Yeung, J. (2002). The EXPLAN theory of fluency control and the diagnosis of stuttering. In E. Fava (Ed.), Current issues in linguistic theory series: Pathology and therapy of speech disorders (pp. 75-94). Amsterdam: John Benjamins].

LEARNING OUTCOMES

After reading this article, the reader will be able to: (1) understand which linguistic levels can be primed in children who stutter; (2) see why EXPLAN predicts asymmetrical effects on fluency when function or content words are primed; (3) appreciate the distinguishing characteristics of CRH and EXPLAN theories.

Speeded verbal responding in adults who stutter: are there deficits in linguistic encoding?

Linguistic encoding deficits in people who stutter (PWS, n=18) were investigated using auditory priming during picture naming and word vs. non-word comparisons during choice and simple verbal reaction time (RT) tasks. During picture naming, PWS did not differ significantly from normally fluent speakers (n=18) in the magnitude of inhibition of RT from semantically related primes and the magnitude of facilitation from phonologically related primes. PWS also did not differ from controls in the degree to which words were faster than non-words during choice RT, although PWS were slower overall than controls. Simple RT showed no difference between groups, or between words and non-words, suggesting differences in speech initiation time do not explain the choice RT results. The findings are consistent with PWS not being deficient in the time course of lexical activation and selection, phonological encoding, and phonetic encoding. Potential deficits underlying slow choice RTs outside of linguistic encoding are discussed.

EDUCATIONAL OBJECTIVES

The reader will be able to (1) describe possible relationships between linguistic encoding processes and speech motor control difficulties in people who stutter; (2) explain the role of lexical priming tasks during speech production in evaluating the efficiency of linguistic encoding; (3) describe the different levels of processing that may be involved in slow verbal responding by people who stutter, and identify which levels could be involved based on the findings of the present study.

Age of acquisition and repetition priming effects on picture naming of children who do and do not stutter

The effects of age of acquisition and repetition priming on picture naming latencies and errors were studied in 22 children who stutter (CWS) and 22 children who do not stutter (CWNS) between the ages of 3;1 and 5;7. Children participated in a computerized picture naming task where they named pictures of both early and late acquired (AoA) words in two consecutive stages. Findings revealed that all children's picture naming latencies and errors were reduced following repetition priming and in response to early AoA words relative to late AoA words. AoA and repetition priming effects were similar for children in both talker groups, with one exception. Namely, CWS benefitted significantly more, in terms of error reduction, than CWNS from repetition priming for late AoA words. In addition, CWNS exhibited a significant, positive association between linguistic speed and measures of vocabulary, but CWS did not. These findings were taken to suggest that the (a) semantic-phonological connections of CWS may not be as strong as those of CWNS, and (b) existing lexical measures may not be sensitive enough to differentiate CWS from CWNS in lexically related aspects of language production.

EDUCATIONAL OBJECTIVES

After reading this article, the learner will be able to: (a) describe the effects of repetition priming and age of word acquisition in speech production; (b) summarize the performance similarities and differences of children who stutter and children who do not stutter on a computerized picture naming task; and (c) compare the results of the present study with previous work in this area.

Signs of developmental stuttering up to age eight and at 12 plus

Clinicians who are familiar with the general DSM-IV-TR scheme may want to know how to identify whether a child does, or (equally importantly) does not, stutter and what differences there are in the presenting signs for children of different ages. This article reviews and discusses topics in the research literature that have a bearing on these questions. The review compared language, social-environmental and host factors of children who stutter across two age groups (up to age eight and 12 plus). Dysfluency types mainly involved repetition of one or more whole function words up to age eight whereas at age 12 plus, dysfluency on parts of content words often occurred. Twin studies showed that environmental and host factors were split roughly 30/70 for both ages. Though the disorder is genetically transmitted, the mode of transmission is not known at present. At the earlier age, there were few clearcut socio-environmental influences. There were, however, some suggestions of sensory (high incidence of otitis media with effusion) and motor differences (high proportion of left-handed individuals in the stuttering group relative to norms) compared to control speakers. At age 12 plus, socio-environmental influences (like state anxiety) occurred in the children who persist, but were not evident in the children who recover from the disorder. Brain scans at the older age show some replicable abnormality in the areas connecting motor and sensory areas in speakers who stutter. The topics considered in the discussion return to the question of how to identify whether a child does or does not stutter. The review identifies extra details that might be considered to improve the classification of stuttering (e.g. sensory and motor assessments). Also, some age-dependent factors and processes are identified (such as change in dysfluency type with age). Knowing the distinguishing features of the disorder allows it to be contrasted with other disorders which show superficially similar features. Two or more disorders can co-occur for two reasons: comorbidity, where the child has two identifiable disorders (e.g. a child with Down Syndrome whose speech has been properly assessed and classed as stuttering). Ambiguous classifications, where an individual suffering from one disorder meets the criteria for one or more other disorders. One way DSM-IV-TR deals with the latter is by giving certain classification axes priority over others. The grounds for such superordinacy seem circular as the main role for allowing this appears to be to avoid such ambiguities.

Analysis of oral narratives of children who stutter and their fluent peers: kindergarten through second grade

Measures of language sample length (in c-units) and morphological, syntactic, and narrative abilities were obtained from oral narrative transcripts of 22 children who stutter and 22 children who do not stutter; participants attended kindergarten, first, and second grades. A two-way MANOVA yielded significant main effects for grade, with significant differences on some measures evidenced between participants in kindergarten and second grades. No significant differences between groups or group-grade interaction effects on the measures were obtained. Grade-wise comparisons (through t-tests) indicated that the performance of children who stutter did not differ significantly from their typically fluent peers on all dependent measures; however, kindergarten children who stutter obtained the most discrepant (lower) scores than their grade-matched fluent peers on the Narrative Scoring Scheme measure, with group differences approaching statistical significance on this measure. The findings suggest that children who do and do not stutter evidence similar expressive language abilities, even as subgroups of children who stutter may lag behind their grade-matched fluent peers in particular language domains.

The role of selected lexical factors on confrontation naming accuracy, speed, and fluency in adults who do and do not stutter

PURPOSE

The purpose of this study was to investigate whether lexical access in adults who stutter (AWS) differs from that in people who do not stutter. Specifically, the authors examined the role of 3 lexical factors on naming speed, accuracy, and fluency: word frequency, neighborhood density, and neighborhood frequency. If stuttering results from an impairment in lexical access, these factors were hypothesized to differentially affect AWS performance on a confrontation naming task.

METHOD

Twenty-five AWS and 25 normally fluent comparison speakers, matched for age and education, participated in a confrontation naming task designed to explore within-speaker performance on naming accuracy, speed, and fluency based on stimulus word frequency and neighborhood characteristics. Accuracy, fluency, and reaction time (from acoustic waveform analysis) were computed.

RESULTS

In general, AWS demonstrated the same effects of lexical factors on their naming as did adults who do not stutter. However, accuracy of naming was reduced for AWS. Stuttering rate was influenced by word frequency but not other factors.

CONCLUSIONS

Results suggest that AWS could have a fundamental deficit in lexical retrieval, but this deficit is unlikely to be at the level of the word's abstract phonological representation. Implications for further research are discussed.

Phonological priming in young children who stutter: holistic versus incremental processing

PURPOSE

To investigate the holistic versus incremental phonological encoding processes of young children who stutter (CWS; N = 26) and age- and gender-matched children who do not stutter (CWNS; N = 26) via a picture-naming auditory priming paradigm.

METHOD

Children named pictures during 3 auditory priming conditions: neutral, holistic, and incremental. Speech reaction time (SRT) was measured from the onset of picture presentation to the onset of participant response.

RESULTS

CWNS shifted from being significantly faster in the holistic priming condition to being significantly faster in the incremental priming condition from 3 to 5 years of age. In contrast, the majority of 3- and 5-year-old CWS continued to exhibit faster SRT in the holistic than the incremental condition.

CONCLUSION

CWS are delayed in making the developmental shift in phonological encoding from holistic to incremental processing, a delay that may contribute to their difficulties establishing fluent speech.